Rotor brake head guide



Oct. M, 1958 F. E. BACHMAN ETAL 2,856,031

RoToR BRAKE HEAD GUIDE l Filed June 15, 1954 2 Sheets-Sheet 1 Get. 14, 3958 F. E. BACHMAN ET AL 2,856,031

- ROTOR BRAKE HEAD GUIDE Filed vJune 15. 195.4 l 2 Sheets-Sheet 2 @Mlga ROTOR BRAKE HEAD GUIDE Fred E. Bachrnan and Albert F. Seelig, `lr., St. Louis, Mo., assignors to American Steel Foundries, Chicago, Ill., a corporation of New Jersey Application .lune 15, 1954, Serial No. 436,382

9 Claims. (Cl. 18S-59) This invention relates to a novel arrangement wherein an intermediate lever enables lever carried brake heads to be maintained in a correct position to engage and disengage associated friction surfaces.

.The general object of the invention is to provide a novel arrangement enabling surfaces of associated friction members to wear evenly by establishing parallelism therebetween.

Another general object of this invention is an arrangement to properly control the pivotal action between a brake lever and brake head by a novel gearing arrangement.

A further object of this invention is an arrangement for non-clogging or self-cleaning gearingbetween mounting block, intermediate member and brake head.

A still further object of this invention is to provide for elimination of rattles in the pivotal action occurring in the engaging and disengaging of the brake head assembly with its related friction member.

These and other objects of the invention will become apparent in the course of the following description, and from an examination of the concerned drawings, wherein:

Figure l is a fragmentary general diagrammatic sketch of a typical brake arrangement to which the invention may be applied.

Figure 2 is a fragmentary sectional bottom plan view of the brake arrangement of Figure l showing in detail the application of the invention to said brake arrangement.

Figure 3 is a fragmentary elevational view partially shown in a section of the structure shown in Figure 2.

Figure 4 is another fragmentary view similar to Figure 3 of a modified form of the invention, and

Figure 5 is a fragmentary side elevational view of the structure shown in Figure 4.

Describing the invention in detail and referring first to Figure l wherein is illustrated a conventional quarter section of a railway car truck having a side frame 2, supported in the usual manner by a wheel and axle assembly 4. The axle assembly 4 includes a rotor 6 which is rigidly secured to said assembly and rotatable therewith. Adjacent the assembly, the frame includes a transom 8 to which may be mounted in any usual or convenient manner a brake housing 10. Extending from one end of the brake housing are brake levers 12, 12, seen to extend longitudinally of the truck and embracing and clasping the rotor 6. Pivotally connected to the brake levers are the brake head assemblies 14, 14.

Referring now to Figure 2, which shows in detail a portion of the brake arrangement diagrammatically shown in Figure l, it will be noted that within the brake housing 1i) there is disposed a mounting block 16, said block being pivotal on an axis 1S within the housing which extends longitudinally of the truck. It is to be understood by those skilled in the art that the mounting block 16 and its related pivotal axis 18 can be omitted and the brake lever 12 can be pivotally supported by the housing 10. Secured to the opposite arms of the mount- Patented Oct. 14, 1958 rice ing block are the brake levers 12, 12, only one lever being shown in FigureZ inasmuch as the arrangement is duplicated on the opposite side of the brake housing 10. The brake lever is pivotally secured to the mounting block 16 by means of a pivotal pin 20, as can be seen in Figure 2. The brake lever 12 extends rearwardly to a point (not shown) where operative connection is made with an actuating cylinder (not shown) as in the usual manner known to those familiar with the art. Forwardly the brake lever 12 extends to a point where a brake head assembly 14 is pivotally mounted at 23.

The brake head assembly consists of a brake head 26 having on one side thereof a friction shoe 42 which is operative to engage a rotated friction surface of rotor 6. On the opposite side of the brake head 26 are extended lugs 2S and 30 spaced vertically apart so as to receive therebetween the forward extremity of brake lever 12, the pivotal connection therebetween being accomplished by pin 23. In addition a non-rattling device 32 may be mounted on the arrangement, said device comprising an arm 33 secured to the underside of the brake lever having a downwardly and horizontally extending arm 34 having hole 36 to receive pin 23. A torsion spiral spring 38 is interposed between the arm 34 of the device 32 and the bottom lug 31B of the brake head 26, the spring serving to maintain the position of the brake head firmly but resiliently on the end of the brake lever 12 and at the same time offering clockwise torque resistance to the intermediate lever, hereinafter described, so as to establish parallelism between the brake shoe and the rotor and keep the -surface 48 of gear lug 44 against the surface of arm 56 of the intermediate lever 52 so the respective gear surfaces are in operative contact with each other at all times.

Now directing attention to Figures 2 and 3, it will be seen that an intermediate lever 52 is pivotally mounted to the lower portion of the brake lever 12 by pin 54. lt will also be noted that on the adjacent sides .of the mounting block 16 and the brake head 26 are disposed two L-shaped gear lugs 44 and 46. It is to be noted that the surfaces of intermediate lever arms 56 and 57 and related surfaces 4S and 50 of gear lugs 44 and 46 are cut or machined in a gear tooth form and preferably that type of form known as an involute having a 30 degree pressure angle.

In the above desrribed arrangement it will be apparent that as brake lever 12 is moved by actuating means (not shown) it rotates counterclockwise (Figure 2) about pin 20 and its forward end carries brake head assembly 14 into contact with the rotor. The torsion spring 38, which is secured at the bottom on the device 32 and at the top by a notch in lug 30, exerts a clockwise torque on the brake shoe assembly with respect to the forward end of lever 12 so as to maintain parallelism between the respective friction surfaces of the brake shoe 42 and the rotor 6. Upon disengagement thereof by clockwise motion of lever 12 about axis 20, the arm 57 of intermediate lever 52 is engaged by gear lug 46 of mounting block 16 and rotated clockwise wherein said arm 56 will engage lug 44 of the brake shoe assembly and cause said assembly to rotate counterclockwise away from rotor 6 and at the same time will compress spring 38.

A particular advantage in employing the above described gear system and spring with intermediate lever arrangement is that a smooth and even motion is achieved during the pivotal action of the brake lever and related brak-e head assembly wherein slack or play between members is virtually eliminated so as to prevent undue rattling as well as wear and deterioration to the gearing mechanism, and at the same time to establish parallelism between associated brake friction surfaces.

Attention is now directed to Figures 4 and 5 wherein is illustrated a modified embodiment of the invention. However, the brake housing, brake lever and brake shoe assembly employed in this embodiment are substantially as those heretofore described, the identical features being designated by numerals heretofore employed in the pre-k vious embodiment. As will be seen from examination of Figures 4 and 5 the intermediate lever and associated cam gearing are disposed within a horizontal slot spaced centrally of the brake lever. The intermediate lever 152 is pivotal about pin 154, brake head lug 44 is replaced by cam gear 144, which is disposed in the horizontal slot of the brake lever and welded to the head which is pivotal about pin 23. Lug 46 is replaced by cam gear 146, which is disposed in the horizontal slot of the brake lever 12 centrally of said lever and welded to the mounting block 16 which is pivotal about pin 20.

The action of the intermediate lever 152 and associated lugs remains essentially the same as described in the first embodiment, the non-rattling device 32 is disposed in the same place and its function remains unchanged.

It is to be understood by those skilled in the art that mounting block f6 and its related pivotal axis 18 can be omitted and the brake lever 12 pivotally supported by the housing 10.

We claim:

l. In a brake arrangement for a railway car truck, the combination of a movable friction surface, a brake head assembly with a friction shoe thereon having a friction surface, a brake housing, a mounting bracket pivotally carried therein, a brake lever pivotally mounted thereon and connected to said brake head assembly, an intermediate lever carried pivotally by said brake lever independently of said assembly and engageable with the mounting bracket and the assembly, and a spring and spring lever associated with the assembly and brake lever to maintain parallelism between friction surfaces, and to maintain continuous contact between the intermediate lever and the mounting bracket and assembly.

2. In a brake arrangement, a wheel and axle assembly, a frame supported thereby, a friction rotor secured to said assembly and rotatable therewith, a brake head assembly engageable with said rotor, a brake lever movably connected to said assembly, a brake housing assembly mounted to said frame and carrying said brake lever pivotally thereon, means to establish -parallelism between the friction surfaces of rotor and brake head assembly, said means comprising an intermediate lever directly pivoted to said brake lever at a point between said brake head assembly and said housing assembly, gear lugs disposed on the adjacent sides of the brake head and housing assemblies and engaging said intermediate lever, means to provide load on the intermediate lever, said means comprising a torsion spring carried on the brake head assembly and a link operatively connecting said spring to the intermediate lever.

3. In a brake arrangement, a rotor, a brake head assembly, a brake mounting, a brake lever supported by said mounting and connected to said assembly, an intermediate member carried centrally of said lever disposed in a horizontal opening therein, a gear lug disposed on said mounting, a second gear lug disposed centrally of said assembly, said lugs disposed so as to engage the intermediate member, a torsion spring carried on said assembly below said lug so as to -actuate said assembly in a blockwise direction when brake lever is actuated in a counterclockwise direction to maintain parallelism between said assembly and said rotor.

4. `In a brake arrangement, a rotor, a brake head assembly, a brake mounting, a brake lever supported by said mounting and connected to said assembly, an intermediate member carried centrally of said lever and disposed in a horizontal opening of said lever, a gear lug disposed on said mounting and a second gear lug disposed centrally of said assembly, said lugs being positioned to engage the intermediate member.

5. ln a brake arrangement for a railway car truck, a movable friction surface, a brake mounting, a brake lever operatively supported thereby and connected to an assembly engageable with the surface, gear lugs on the mounting and on the assembly, an intermediate lever pivotally carried on the brake lever and engageable with the respective gear lugs of the brake lever mounting and the apssembly, and a torsion spring carried by the assembly, said spring having its opposite ends connected to the assembly and the brake lever whereby said intermediate lever is maintained in operative contact with the lugs.

6. In a brake arrangement for a railway car truck, a combination of: a movable friction surface, a brake sup port means carried by the truck; a brake lever fulcrumed to said support means, a brake shoe assembly pivoted to the brake lever, said assembly having a friction surface engageable with the first-mentioned surface, a lug on said brake shoe assembly, a lug on said support means, an intermediate lever entirely supported and pivotally carried by said brake lever between said support means and assembly, said intermediate lever comprising arms extending towards said support means and assembly, said arms engaging said lugs, and resilient means operatively connected to said assembly and brake lever, said resilient means being disposed to maintain said lugs and arms in continuous engagement with each other.

7. In a brake arrangement for a railway car truck, a combination of: a friction surface, a brake mounting, a brake lever pivotally connected to said mounting along a pivotal axis, a brake shoe assembly comprising a brake head and a brake shoe, said shoe being engageable with said surface, said brake head being pivotally connected to said lever along a pivotal axis substantially parallel to the rst-mentioned axis, an intermediate lever pivotally connected to said brake lever along a pivotal axis disposed between and substantially parallel to the rst-mentioned axes, a lug on said brake head, said lug extending towards said intermediate lever, a lug on said mounting, said mounting lug extending towards said intermediate lever, a pair of lugs on said intermediate lever, one of said pair of lugs extending towards and abuttably engaging said mounting lug, the other of said pair extending towards and abuttably engaging said brake head lug, and a torsion spring having the opposite ends thereof connected to the brake head and brake lever whereby said intermediate lever lugs are maintained in continuous contact with the lugs on the brake head and mounting.

8. In a brake arrangement, a rotatable member having a friction surface thereon, a friction shoe assembly having a friction surface engageable with said first-mentioned surface, a brake lever pivotally carrying said assembly, a mounting member pivotally carrying said brake lever, a lug on said assembly extending towards said mounting member, a lug on said mounting member extending towards said assembly, an intermediate lever pivotally carried by said brake lever along a pivotal axis spaced from said lugs, said intermediate lever having arms extending towards and engaging said lugs, said arms and lugs each defining a standard gear form, and resilient means maintaining engagement of said lugs and arms, said means comprising a torsion spring carried by said assembly, said torsion spring having an end thereof connected to said assembly, and a link connecting the brake lever and the other end of said spring.

9. In a brake arrangement, a rotatable friction member having a friction surface thereon, a friction shoe assembly having a surface engageable with said rst-mentioned surface, a brake lever pivotally carrying said assembly, a mounting block pivotally carrying said lever, an intermediate lever pivotally connected to said brake lever intermediate said assembly and block, a gear-shaped lug carried by said block, a gear-shaped lug carried by References Cited in the le of this patent said assembly, gear-shaped arms on said intermediate UNTED STATES PATENTS lever extending towards and engaging said lugs, a torsion 3431,68() Tribe June 15) 1886 spring carried by tlie assembly .and operatively connected 5 735,636 Whitmore Aug' 4y 1903 thereto, and a torsion link carried by the brake lever and 2,148,791 Whitney Feb 2g 1939 operatively connected to the spring, said link comprising 2,355,120 Tack Aug, 8, 1944 arms securely connected to the brake lever and spring. 2,363,453 Tack Nov. 2l, 1944 

